Disk array apparatus

ABSTRACT

For achieving installation of disk drives at high density, as well as, a large capacity and a high speed of the disk array apparatus, the disk array apparatus comprises disk drives, a box containing a large number of the disk drives in a direction of thickness thereof, wherein a throttle of flow passage, which combines a sour absorbing material in common, is provided above the disk drives in the downstream side of the disk array apparatus.

BACKGROUND OF THE INVENTION

The present invention relates to a disk array apparatus.

In the disk array apparatus, the disk drives of a magnetic-type or anoptical-type are contained within a housing, a large number thereof, soas to improve the reliability in data reservation. Those disk arrayapparatuses are connected through a high-speed network for exclusive usethereof, such as, applying a light therein, for example, wherein theyare operated by means of management software, to be used in the form of,SAM (Storage Area Network), NAS (Network Attached Storage), or anindependent RAID (Redundant Array of Inexpensive Disks), for example.

Each of those disk drives, to be installed into those disk arrayapparatuses, is built up with a disk main body, comprising a magneticdisk, a drive motor, an actuator, etc., within an inside thereof, andconnectors for use of electronic parts for control, etc. Mainheat-generation sources in the disk drive include the drive motor, theactuator, and the control-use electronic parts, in the form of a LSI.Heats generated from those parts are cooled down with an aid of coolingwind generated by a cooling fan, which is attached on the housing of thedisk array. If cooling capacity is deteriorated, then temperature of thedisk drive goes up, and thereby generating unevenness among the pluralnumber of disk drives; therefore, there is a possibility that it causeserroneous operations or deteriorates the reliability thereof.

For example, if there is the unevenness in temperature among the diskdrives, there is caused a shit in timing of the electronic parts; i.e.,a possibility of causing defects in the operation of accessing from thecontroller to the disk drive, or generating a delay in the time for datatransmission. Also, if temperature goes up in the disk drive,deterioration is caused ion a lubrication layer pasted upon the disksurface, and therefore the disk can be damaged, easily.

Also, the magnetic disk, the drive motor, or the actuator, etc.,included within an inside of the disk drive, defines an operatingportion, and also defines a noise generating portion, at the same time.When installing the disk drives, each having such the noise source, by alarge number thereof, then it is of course to increase the noisesgenerated therefrom. Also, even noises cannot be neglected, which aregenerated from the fan for driving an air-flow within the disk arrayapparatus.

In this manner, within the disk array apparatus, there are two (2)problems to be dissolved, i.e., of obtaining an equal cooling of thedirk drives, and also of silencing the noises of the disk drives and anapparatus.

With the conventional disk array apparatus, mounting the disk drives andthe controller circuit within the same surface on a board, it is alreadyknow to provide an air-guide plate, thereby dividing the cooling flowpassages for the disk drives and the controller circuit (please see thefollowing Patent Document 1).

Or, with the conventional disk array apparatus, a measure is made ofseparating the flow passage, including the disk drives therein, and theflow passage, including the controller circuit therein, so as toequalize the cooling therebetween (please see the following PatentDocument 2).

Further, with the conventional disk array apparatus, there is alreadydisclosed the structure of disposing the disk drives in a zigzag manner(please see the following Patent Document 3).

Also, with the magnetic disk apparatus, there is already disclosed acooling controller plate for increasing the velocity of winds passing bythe side of a printed board (please see the following Patent Document4).

Patent Document 1: Japanese Patent Laying-Open No. Hei 9-274791 (1997);

Patent Document 2: Japanese Patent Laying-Open No. 2001-338486 (2001);

Patent Document 3: Japanese Patent Laying-Open No. Hei 5-54626 (1993);and

Patent Document 4: Japanese Patent Laying-Open No. 2001-344961 (2001).

With the conventional technology described in the Patent Document 1,since the disk drives and the controller are mounted on the same board,therefore the number is restricted of the disk drives, which can beinstalled therein. Also, there is no problem of equalizing thetemperature distribution among the disk drives.

With the conventional technology described in the Patent Document 2,though the disk drives and the controller are mounted on the same board,however there is no problem of equalizing the temperature distributionamong the disk drives when a plural number of the disk drives areinstalled aligning with the flow direction.

With the conventional technology described in the Patent Document 3,although flow resistance is increased, however since acceleration ismade upon mixing of the cooling airs flowing on side surfaces of thedisk drives, therefore an improvement can be obtained on the coolingcharacteristics of the disk drives. However, when the disk drives aredisposed within the cooling flow path by a large number thereof, becausethere is a large space above the disk drives, there is a problem thatthe cooling air of downstream bypasses through the space above the diskdrives, in particular, in the zigzag arrangement where the flowresistance is large; i.e., there is no problem of equalizing thetemperature distribution among the disk drives.

With the conventional technology described in the Patent Document 4,although an improvement can be obtained on the cooling performances ofthe disk drive by itself, however there is no disclosure of thestructures for cooling a group of the disk drives as a whole, inparticular, when a plural number of disk drives are disposed in thedownstream side; i.e., there is no problem of equalizing the temperaturedistribution among the disk drives.

Also, with those conventional technologies relating to the PatentDocument 1 to the Patent Document 4, there is disclosed the structuresfor reducing the noises generated within the disk array apparatus.

BRIEF SUMMARY OF THE INVENTION

An object according to the present invention is to provide a disk arrayapparatus obtaining an equalization of cooling among the disk drives, aswell as, reduction of noises within the apparatus thereof.

For accomplishing the object mentioned above, according to the presentinvention, there is provided a disk array apparatus, comprising: diskdrives, which are mounted on a plural number of lines, in a direction ofproceeding of an air flow; a housing containing said disk drivestherein; and flow passages provided between an upper surface of saiddisk drives and an inner wall of an upper surface of said housing, forallowing said air flow to pass through, wherein a dam is provided fornarrowing said air flow, above said disk drives, in a downstream side ofsaid flow passages.

And, the above object mentioned above is accomplished by the disk arrayapparatus, as described in the above, wherein said dam is made of asound absorbing material and said dam is attached on the inner wall ofthe upper surface of said housing.

Also, for accomplishing the object mentioned above, according to thepresent invention, there is further provided a disk array apparatus,comprising: disk drives, which are mounted on a plural number of lines,in a direction of proceeding of an air flow; a housing containing saiddisk drives therein; and flow passages provided between an upper surfaceof said disk drives and an inner wall of an upper surface of saidhousing, for allowing said air flow to pass through, wherein a shieldplate is provided for shielding a direction of the air flow passingthrough said disk drives, in a downstream side of said flow passages,and on said shielding plate are provided openings corresponding toshapes of said disk drives.

And, the above object mentioned above is accomplished by the disk arrayapparatus, as described in the above, wherein said shield plate is sodisposed that spaces are opened alternately in a direction of height ina front and a rear of said disk drives.

Also, the above object mentioned above is accomplished, by the diskarray apparatus, as described in the above, wherein a heat sink isattached on one of sidewalls of each of said disk drives.

And, also the above object mentioned above is accomplished, by the diskarray apparatus, as described in the above, wherein a dummy is attachedat a position where said disk drive is not installed.

Thus, according to the present invention, it is possible to provide adisk array apparatus obtaining an equal cooling of the disk drives, aswell as, silence of the disk drives and/or an apparatus.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

Those and other objects, features and advantages of the presentinvention will become more readily apparent from the following detaileddescription when taken in conjunction with the accompanying drawingswherein:

FIG. 1 is a cross-section view for showing the structures of the diskarray apparatus, according to a first embodiment of the presentinvention;

FIG. 2 is a brief structural view for showing a backboard in the firstembodiment of the present invention;

FIGS. 3(a) and 3(b) are enlarged partial views for showing the diskarray apparatus, according to the first embodiment of the presentinvention;

FIGS. 4(a) and 4(b) are enlarged partial views for showing the diskarray apparatus, according to a second embodiment of the presentinvention;

FIGS. 5(a) and 5(b) are enlarged partial views for showing the diskarray apparatus, according to a third embodiment of the presentinvention;

FIGS. 6(a) and 6(b) are views for showing the detailed structures of athrottle in flow passage, according to the third embodiment of thepresent invention;

FIGS. 7(a) and 7(b) are enlarged partial views for showing the diskarray apparatus, according to a fourth embodiment of the presentinvention;

FIG. 8 is a view for showing the detailed structures of a throttle inflow passage, according to the fourth embodiment of the presentinvention;

FIGS. 9(a) and 9(b) are enlarged partial views for showing the diskarray apparatus, according to a fifth embodiment of the presentinvention;

FIGS. 10(a) and 10(b) are enlarged partial views for showing the diskarray apparatus, according to a sixth embodiment of the presentinvention;

FIG. 11 is a view for showing the detailed structures of a disk drive,according to the sixth embodiment of the present invention;

FIG. 12 is a the cross-section view for showing the structures of a diskdrive, according to a seventh embodiment of the present invention;

FIG. 13 shows a graph for showing effects of the present invention;

FIG. 14 is a perspective view for showing the disk array apparatus,according to the present invention;

FIG. 15 is a perspective view for showing a system of the disk arrayapparatus, according to the present invention; and

FIG. 16 is also a perspective view for showing a system of the diskarray apparatus, according to the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Hereinafter, embodiments according to the present invention will befully explained by referring to the attached drawings.

Explanation will be given about a first embodiment according to thepresent invention, by referring to FIGS. 1 to 3(b).

EMBODIMENT 1

FIG. 1 is a cross-section view of the disk array apparatus, according tothe present embodiment.

FIG. 2 is a brief structural view of a backboard, according to thepresent invention.

FIG. 3(a) is a partial sides view of the disk array apparatus, accordingto the present invention, and FIG. 3(b) is an upper view of FIG. 3(a).

FIG. 14 is a perspective view of the disk array apparatus, according tothe present invention.

In the figures, within a housing 1 of the disk array apparatus, aportion of installing a large number of disk drives 2 is disposed in afront, while an electric power source 6 and a controller circuit board 7are installed in a rear portion thereof. Also, at the end there of isprovided a fan unit 8. The disk drives 2 are connected onto amotherboard 4 through connectors 3. The motherboard 4 is connected to abackboard 5 with an aid of wiring (not shown in the figure). Also, theelectric power source 6 and the controller circuit board 7 are connectedonto the backboard 5 through connectors 3′. On the backboard 5 areprovided airflow orifices 9, as is shown in FIG. 2. Those airfloworifices 9 are provides so that a numerical aperture comes to be almostequal or uniform to all over an area of the backboard.

However, in the present embodiment, among the connectors 3 on themotherboard 4, a dummy (disk drive) is mounted in a portion, on which nodisk drive 2 is mounted. The dummy is adjusted so as to have the flowresistance same to that of the disk drive 2, and it is a box having theouter sizes thereof, for example, which is same to that of disk drive 2.This is also same to other embodiments.

In the present embodiment, maintenance of the disk drive 2 is made byopening a cover, which is provided in a front upper portion of thehousing 1, after drawing out the housing 1 from a container portionthereof. In case where a large number of disk drives 2 are installed,like in the present case, there is necessity of a room in the sense ofspace, for allowing the disk drives 2 to be inserted/drawn out upwards.

In the present embodiment, above the disk drives 2 on the downstreamside is provided a throttle 10 of flow path (i.e., a dam). This flowpath throttle 10 has the structure combining a sound absorbing materialin common.

In such structures, cooling wind driven by the fan unit 8 flows intofrom a front of the housing 1, and after cooling the respective diskdrives 2, it passes through the backboard 5. Further, after cooling theelectric power source 6 and the control board 7, it is discharged from arear side of the housing 1. However, because the numerical aperture isalmost equal about the airflow orifices 9, which are provided in thebackboard 5, flow velocity of the flow through the disk drives 2 comesto be nearly constant in the cress-section of the flow passage. In thisinstance, since being heated by the heat-generation body, which isdisposed on the way thereof, the cooling wind raises up temperaturethereof, as it comes down to downstream. For this reason, thetemperature of the disk drives 2 in the downstream side increases,comparing to that of the disk drives in the upstream side. However, inthe present embodiment, due to the function of the flow path throttle10, which is provided upwards the disk drives 2 in the downstream side,the flow passage is reduced or narrowed, then the cooling wind, beingcut off from escape, flows into the side of the disk drives 2, and ithits on the disk drives 2 with increasing wind velocity thereof;therefore, cooling is preferable, in particular, for the disk drives 2in the downstream side. With this, it is possible to lessen theunevenness or fluctuation on temperature of the disk drives 2 betweenthe upstream side and the downstream side.

Also, since the numerical aperture of the airflow orifices 9, which areprovided in the backboard 5 by a large number thereof, is almost equalto the cross-section of flow passage, and dummies are mounted on theportion where the disk drives 2 are not mounted, therefore the flowvelocity through the disk drives 2 is nearly constant on thecross-section of flowpassage; i.e., it is possible to lessen theunevenness in temperature on the disk drives 2, in particular, in thedirection of the cross-section of flow passage.

According to the present embodiment, it is possible to bring therespective disk drives 2 into preferable conditions thereof whilealigning the disk drives 2, as they are, ordinarily.

According to the present embodiment, since cooling can be madeeffectively by means of the fan unit 8 having a small capacity thereof,it is possible to reduce the noises coming out from the fan. Also, theflow path throttle 10 has the structures combining the sound absorbingmaterial, in common with; therefore it is possible to absorb the noisesgenerated by the respective disk drives 2 with high efficiency.

EMBODIMENT 2

FIGS. 4(a) and 4(b) are views for showing a second embodiment, in thesimilar manner to FIGS. 3(a) and 3(b).

In those FIGS. 4(a) and 4(b) are arranged the disk drives 2 also in thezigzag manner, and with this, though increasing the flow resistancethereof, however mixture of cooling airs can be accelerated among thedisk drives 2; therefore, further preferable cooling performances can beobtained.

Further, there is also provided the flow path throttle 10, being made upwith the material having sound absorbing characteristics above of thedisk drives 2 in the downstream side. With this, it is possible toremove a problem that is caused when disposing the large number of diskdrives within the cooling flow passage, i.e., flow of the cooling air onthe downstream side bypassing into the upper space of the disk drives.Further, the cooling wind flowing above the disk drives 2, but not beingheated, hits onto the disk drives 2 while increasing the wind velocitythereof; therefore, the cooling obtained in the disk drives 2 on thedownstream side are very preferable. With this, it is possible to makethe unevenness in the increase of temperature small, in particular,between the disk drives 2 in the upstream and the downstream.

According to the present embodiment, since effective cooling can beobtain even by the fan unit 8 having small capacity thereof, thereforeit is possible to reduce the noises generated from the fan. Also, theflow path throttle 10 has the structures combining the sound absorbingmaterial, in common with; therefore it is possible to absorb the noisesgenerated by the respective disk drives 2 with high efficiency.

EMBODIMENT 3

FIGS. 5(a) and 5(b) and 6(a) and 6(b) are views for showing a thirdembodiment, and FIGS. 5(a) and 5(b) are similar views of FIGS. 3(a) and3(b).

FIGS. 6(a) and 6(b) are views for showing the details of a flow paththrottle 10′, according to the present embodiment.

Within the present embodiment, the flow path throttle 10′ is made from aplate having a large number of openings 9′ therein, and each of theopenings 9′ are corresponding to the position of the each disk drive 2,respectively. Namely, it is so designed that the cooling winds comegather into outer periphery portions of the disk drives 2. In theembodiment shown in FIGS. 5(a) and 5(b), the flow path throttles 10′ areprovided, in a front and a rear of the disk drives 2. Further, also inthe present embodiment, the flow path throttle 10′ is made of a materialhaving the sound absorbing characteristics.

In such the structures, due to the function of the flow path throttle10′ provided in the front and the rear of the disk drives 2 on thedownstream side, the flow passage is reduced or narrowed, locally, andthe cooling winds not heated so much, flowing above the disk drives 2and at a center of the disk drives 2, hit onto the disk drives 2 withincreasing the wind velocity thereof, and therefore, preferable coolingcan be obtained at portions, in particular, at a front edge and a rearedge portions, on the disk drives 2 on the downstream side. With this,it is possible to lessen the unevenness or fluctuation on temperature ofthe disk drives 2 between the upstream side and the downstream side.

Also, the numerical aperture of the large number of openings 9′, whichare provided on the flow path throttle 10′, is equal to thecross-section of the flow passage, and dummies are mounted on theportion where the disk drives 2 are not mounted, therefore the flowvelocity through the disk drives 2 is nearly constant on thecross-section of flow passage, completely; i.e., it is possible tolessen the unevenness in temperature on the disk drives 2 in thedirection of the cross-section of flow passage.

According to the present embodiment, it is possible to bring therespective disk drives 2 into preferable conditions thereof whilealigning the disk drives 2, as they are, ordinarily.

According to the present embodiment, since cooling can be madeeffectively by means of the fan unit 8 having a small capacity thereof,it is possible to reduce the noises coming out from the fan. Also, theflow path throttle 10′ has the structures combining the sound absorbingmaterial, in common with; therefore, it is possible to absorb the noisesgenerated from the respective disk drives 2, with high efficiency.

EMBODIMENT 4

FIGS. 7(a) and 7(b) and FIG. 8 are views for showing a fourthembodiment, and FIGS. 7(a) and 7(b) are enlarged partial views of thedisk array apparatus, according to the present embodiment.

FIG. 8 is a view for showing the detailed structure of a flow paththrottle 10″ according to the present embodiment.

In FIGS. 7(a) and 7(b) and FIG. 8, the flow path throttle 10″ is madefrom a plate having a large number of projections 11 on a lower sidethereof, and the positions of those projections 11 are corresponding toa central position between the disk drives 2, respectively. Within theembodiment shown in FIGS. 7(a) and 7(b), the projections 11 are providedat the positions of the disk drives 2 on the most downstream side.Namely, it is so designed that the cooling winds come gather around thedisk drives 2 on the most downstream side, in particular. Further, alsoin the present embodiment, the flowpath throttle 10″ is made of amaterial having the sound absorbing characteristics.

In the present embodiment, due to the faction of the flow path throttle10″, which are provided above the disk drives 2 on the downstream side,the flow passage is reduced or narrowed for the disk drives 2 on thethird line and thereafter, the cooling wind not heated, flowing abovethe disk drives 2 hits onto the disk drives 2 with increasing the windvelocity thereof; therefore, preferable cooling can be obtained on thedisk drives in the down streamside. Further, with the disk drives 2 onthe fourth line, the cooling wind flows around the disk drives 2, beingfurther accelerated by means of the projection 11, and therefore thecooling obtained on the disk drives 2 comes to be very preferable.

With this, it is possible to make the unevenness in the increase oftemperature small, in particular, between the disk drives 2 in theupstream and the downstream.

Also, due to the functions of the projections 11, which are provided onthe flow path throttle 10″, since the flow resistance is controlled whenthe cooling wind flows through the flow passage, it is possible tolessen the unevenness in temperature on the disk drives 2, inparticular, in the direction of the cross-section of flow passage.

According to the present embodiment, it is possible to bring therespective disk drives 2 into preferable conditions thereof whilealigning the disk drives 2, as they are, ordinarily.

According to the present embodiment, since cooling can be madeeffectively by means of the fan unit 8 having a small capacity thereof,it is possible to reduce the noises coming out from the fan. Also, theflow path throttle 10″ has the structures combining the sound absorbingmaterial, in common with; therefore, it is possible to absorb the noisesgenerated from the respective disk drives 2, with high efficiency.

EMBODIMENT 5

FIGS. 9(a) and 9(b) are views for showing a fifth embodiment, and areenlarged partial views of the disk array apparatus, according to thepresent embodiment.

Flowpath throttles 10″′, according to the present embodiment, each beingmade from a plate having on opening portion therein, are located in afront and a rear of two (2) lines of disk drives in the downstream side,so that a space can be opened in the direction of height. Also, in thepresent embodiment, the flow path throttles 10″40 are made of a materialhaving the sound absorbing characteristics.

In such the structures, due to the functions of the flow path throttles10″′, which are provided in the front and the rear of the disk drives inthe downstream side, the cooling wind flowing above the disk drives 2and in the center between the disk drives 2, hits onto the disk drives 2while flowing in a zigzag manner into up and down directions and alsoincreasing the wind velocity thereof; therefore, preferable cooling canbe obtained on the disk drives 2 in the downstream side. With this, itis possible to make the unevenness in the increase of temperature small,in particular, between the disk drives 2 in the upstream and thedownstream.

According to the present embodiment, it is possible to bring therespective disk drives 2 into preferable conditions thereof whilealigning the disk drives 2, as they are, ordinarily.

According to the present embodiment, since cooling can be madeeffectively by means of the fan unit 8 having a small capacity thereof,it is possible to reduce the noises coming out from the fan. Also, theflow path throttle 10″′ has the structures combining the sound absorbingmaterial, in common with; therefore, it is possible to absorb the noisesgenerated from the respective disk drives 2, with high efficiency.

EMBODIMENT 6

FIGS. 10(a) and 10(b), and FIG. 11 are views for showing a sixthembodiment, and FIGS. 10(a) and 10(b) are enlarged partial views of thedisk array apparatus, according to the present embodiment.

FIG. 11 is a view for showing the detailed structures of a disk drivehaving a heat sink, according to the present embodiment.

In those FIGS. 10(a) and 10(b), and FIG. 11, a heat sink 12 is attachedon one of sidewalls of the disk drive 2. In the present embodiment,though there is only shown the heat sink 12 of a shape, having a largenumber of plates aligned, however the heat sink should not be restrictedto this, in the shape thereof, and it may be in any kind of shapes, asfar as it can increase an area for heat radiation.

Also, in the present embodiment, above the disk drives 2 in thedownstream side, there is provided the flow path throttle 10, which ismade of a material having the sound absorbing characteristics, in thesimilar manner to the first embodiment.

In such the structures, due to the functions of the heat sink 12, verypreferable cooling of the respective disk drives 2 can be achieved.Further, due to the functions of the flow path throttle 10, which isprovided above the disk drives in the downstream side, the flow passageis reduced or narrowed, and therefore the cooling wind not heated,flowing above the disk drives 2, hits onto the disk drives 2 withincreasing the wind velocity thereof; therefore, further preferablecooling can be obtained on the disk drives 2 in the downstream side.With this, it is possible to make the unevenness in the increase oftemperature small, in particular, between the disk drives 2 in theupstream and the downstream.

Further, if it is so designed that the number of pieces of fins of theheat sink is much more, for the disk drives 2 in the downstream side, itis further possible to reduce the unevenness in the increase oftemperature, in particular, between the disk drives 2 in the upstreamside and the downstream side, much more.

According to the present embodiment, since cooling can be madeeffectively by means of the fan unit 8 having a small capacity thereof,it is possible to reduce the noises coming out from the fan. Also, theflow path throttle 10 has the structures combining the sound absorbingmaterial, in common with; therefore, it is possible to absorb the noisesgenerated from the respective disk drives 2, with high efficiency.

EMBODIMENT 7

FIG. 12 is a view for showing a seventh embodiment, and is across-section view of the structures of the disk array apparatus,according to the present embodiment. In this FIG. 12, above all the diskdrives 2 are provided the flow path throttles 10, which are made of amaterial having the sound absorbing characteristics.

With such the structures, no cooling air bypasses above the disk drives2, preferable cooling can be obtained for the respective disk drives 2.Also, cooling can be made effectively by means of the fan unit 8 havinga small capacity thereof; therefore, it is possible to reduce the noisescoming out from the fan. Further, the flow path throttle 10 has thestructures combining the sound absorbing material, in common with;therefore, it is possible to absorb the noises generated from therespective disk drives 2, with high efficiency.

FIG. 13 is a graph for showing an example of effects, which can beobtained, according to the present invention.

In this FIG. 13, first of all, explanation will be made about theoperations of the disk drives 2.

Upon receipt of a command transmitted from the controller, the diskdrives 2 is turned into any one of “Ready”, “Not Ready” and “Power OFF”in the operation condition thereof. Among of those, the disk drives 2operating under the “Ready” condition are able to receive a command ofreading/writing data, which is transmitted from the controller. The diskdrives 2 operating under the “Ready” condition are rotating at therotation speed necessary for conducting the reading/writing of data.FIG. 13 shows the maximum values of an increase of temperature on thedisk drives 2, under an idling condition where no data is read/writtenunder the “Ready” condition. For the disk array apparatus, it is generalto take the maximum value of the increase in temperature to be about 15°C. With the conventional art, it comes up to about 15° C. under theidling condition, and therefore cooling cannot be conducted upon thedisk drive 2 under the condition of reading/writing of data. Accordingto the present invention, there can be obtained a room in thetemperature, then cooling can be conducted upon the disk drives 2 underthe condition of reading/writing data thereon. For example, under thecondition of the embodiment 3, cooling can be obtained, fully, even whenall the disk drives 2 are operating on a load equal or greater than 50%of the maximum load thereof. By the way, if the disk drives increase thenumber thereof, there is no chance that all the disk drives 2 areoperated under the maximum load condition thereof.

Thus, in case of the disk array apparatus according to the presentinvention, it is possible to improve the cooling performances of thedisk drives, and to suppress the unevenness of temperature, and in itsturn to obtain an improved reliability and a long lifetime of the diskdrives, as well as, enabling an installation of disk drives at highdensity, and obtaining a large capacity and high speed of the disk arrayapparatus. And, it is also possible to provide a disk array apparatus oflow noises.

EMBODIMENT 8

An eighth embodiment according to the present invention is shown inFIGS. 15 and 16. Those FIGS. 15 and 16 show a system of the disk arrayapparatus, according to the present embodiment.

In the present embodiment, the housings 1 of the disk array apparatuses,which are described in the embodiments 1 to 7, are installed within aninside of a system housing 100, in the vertical direction, by a largenumber thereof.

FIG. 15 shows an example of applying a standard rack as the systemhousing 100, in which the housings in the large number thereof 1 areinstalled in the direction of height thereof. With such the structures,since cooling can be made effectively by means of the fan unit 8 havinga small capacity thereof, it is possible to reduce the noises coming outfrom the fan.

In the embodiment shown in FIG. 16, the housings 1 are installed on thefront and the rear surfaces (in other words, in the direction of bothsides) of the system housing, into the vertical direction thereof, by alarge number thereof. Also, within the system housing 100 are provided asystem fan unit 101, and a system electric power source 102. With suchthe structures, since cooling can be made effectively by means of thefan unit 8 having a small capacity thereof, it is possible to reduce thenoises coming out from the fan, as well as, heats discharged from therespective housings 1 can be discharged into an outside of the systemhousing 100, smoothly, due to the functions of the system fan units 101.

The present invention may be embodied in other specific forms withoutdeparting from the spirit or essential feature or characteristicsthereof. The present embodiment(s) is/are therefore to be considered inall respects as illustrative and not restrictive, the scope of theinvention being indicated by the appended claims rather than by theforgoing description and range of equivalency of the claims aretherefore to be embraces therein.

1. A disk array apparatus, comprising: disk drives, which are mounted ona plural number of lines, in a direction of proceeding of an air flow; ahousing containing said disk drives therein; and flow passages providedbetween an upper surface of said disk drives and an inner wall of anupper surface of said housing, for allowing said air flow to passthrough, wherein a dam is provided for narrowing said air flow, abovesaid disk drives, in a downstream side of said flow passages.
 2. Thedisk array apparatus, as described in the claim 1, wherein said dam ismade of a sound absorbing material, and said dam is attached on theinner wall of the upper surface of said housing.
 3. A disk arrayapparatus, comprising: disk drives, which are mounted on a plural numberof lines, in a direction of proceeding of an air flow; a housingcontaining said disk drives therein; and flow passages provided betweenan upper surface of said disk drives and an inner wall of an uppersurface of said housing, for allowing said air flow to pass through,wherein a shield plate is provided for shielding a direction of the airflow passing through said disk drives, in a downstream side of said flowpassages, and on said shielding plate are provided openingscorresponding to shapes of said disk drives.
 4. The disk arrayapparatus, as described in the claim 3, wherein said shield plate is sodisposed that spaces are opened alternately in a direction of height ina front and a rear of said disk drives.
 5. The disk array apparatus, asdescribed in the claim 3, wherein a heat sink is attached on one ofsidewalls of each of said disk drives.
 6. The disk array apparatus, asdescribed in the claim 3, wherein a dummy is attached at a positionwhere said disk drive is not installed.